Many students probably have a basic understanding of Pavlov's foray into "classical conditioning," by which the Russian scientist trained dogs to salivate upon the sound of a metronome. But as Chapter 6 tells us, classical conditioning may extend as far as human phobias and fetishes. Each is part of the broader learning process, "learning" defined as "change in an organism's behavior or thought as a result of experience" (202).
While for Pavlov's dogs, the original response to the metronome was neutral, he started inserting meat powder into their salivary glands, upon which they began salivating. However, with the sound of the metronome and the flavor of meat powder combined, the dogs began to elicit the same response from both, and began salivating even when only hearing the metronome, a previously nonexistent response.
The same sort of conditioning may apply in developing phobias and fetishes. I, for one, have a deathly fear of mice, but maybe my phobia became engrained because of another object associated with the mice (like how the metronome became associated with the meat powder).
Fortunately, those who harbor powerful fetishes probably had a more "pleasurable" conditioning experience. Whether we learn through classical conditioning or the consequences of our actions, the learning process is shrouded in deep, dark - perhaps erotic? - secrecies.